Due to use of Submission.{choices, options, bet_options} in realbody,
generating submission_listings resulted in extremely high volume of
SELECT queries.
In local testing with 6 posts, one of which had a poll with 2 options,
the removal of these calls reduced quantity of queries on the homepage
from 84 to 22.
Given that it was previously decided to remove the polls feature after
a regression while adding comment filtering, the remaining dead code
paths for polls were also removed.
dbaf0a1bfd